Lavatory freshening and/or cleaning system and method

ABSTRACT

A lavatory freshening and/or cleaning system comprises a dispenser for dispensing a liquid composition from under the rim of a lavatory bowl. The dispenser is in the form of a reservoir arranged for suspension from the rim of lavatory bowl, and the reservoir contains the liquid composition. The liquid composition comprises a combination of anionic and non-ionic surfactants having a total concentration of 22.5 wt. %, a thickening agent having a concentration of 0.40 wt. % and a perfume having a concentration of 6.00 wt. % and having a viscosity of a bout 3,500 mPa s.

This invention relates to a freshener and/or cleaner system for thelavatory and to a method of using such a system in a lavatory bowl. Inparticular, this invention relates to a system comprising a liquidfreshening and/or cleaning composition and a liquid dispenser.

Several lavatory freshening and/or cleaning systems are known. Thesesystems include “solid block” type systems, where a freshening and/orcleaning block is placed either under the rim of the lavatory or in thecistern. In the case of the under the rim system, water dissolves partof the block each time the lavatory is flushed, allowing the lavatorybowl to be cleaned and/or freshened. In the case of the cistern blocksystem, part of the block dissolves in the cistern prior to flushing andthe toilet is cleaned and freshened on flushing of the water held in thecistern into the lavatory bowl. However, solid toilet blocks havedemonstrated several drawbacks, in particular their inability to deliverconstant amounts of cleaning and freshening agents during the lifetimeof the block.

Other freshening and cleaning systems are of the liquid-dispensing type.Such systems include a liquid dispenser and a liquid freshening and/orcleaning composition. A liquid dispenser suitable for such a system isdisclosed in the applicant's published international patent applicationWO 99/66139. Such liquid dispensers generally comprise a reservoir and aliquid-conveying device in the form of a pad, or a plate havingcapillary channels formed therein, the liquid-conveying device and thereservoir being so connected as to allow the freshening and/or cleaningcomposition held in the reservoir to be transferred to theliquid-conveying device in a controlled manner. The liquid dispenser ispositioned under the rim of a lavatory such that, during flushing, asufficient amount of freshening and/or cleaning composition istransferred to the lavatory bowl to effect the cleaning of the bowl.

In order for liquid cleaning systems to be effective, the liquiddispenser must be provided with a suitable liquid cleaning and/orfreshening composition. It is desirable that such a liquid compositionpossess certain properties in order to carry out its freshening and/orcleaning functions. In particular, it is desirable that, when thecomposition is dispensed by flushing, sufficient foaming occurs. Foamingis desirable in order to promote cleaning of the lavatory bowl anddispersal of any perfume which is contained in the composition. Foamingalso confers certain aesthetic properties when the toilet is flushed.

A known liquid cleaning composition, stated to be suitable for liquidcleaning systems of the type hereinbefore described, is disclosed inEuropean patent application EP-A-0 775 741, which describes acomposition having a viscosity at room temperature of 10 to 2 000 mPa sand comprising:

-   -   (a) 1 to 25 wt. % of perfume,    -   (b) 10 to 50 wt. % of anionic or non-ionic surfactant,    -   (c) 1 to 20 wt. % of non-evaporating, water soluble evaporation        regulator, and    -   (d) balance solvent.

As used herein, the term “viscosity” refers to the dynamic viscosity, asmeasured using a Brookfield viscometer (spindle no. 3, 12 rpm, 30seconds at 20° C.). The above range of values for the viscosity isbelieved to be typically used for reasons of economy and ease ofmanufacture.

However, dispensers incorporating such liquids have been found, undercertain circumstances, to draw the flushing water into the reservoir.This effect can lead to a reduction in the concentration of the activecomponents in the liquid contained in the reservoir, and hence acorresponding reduction in the quantity of the active componentstransferred to the lavatory bowl, over the lifetime of the reservoir. Inparticular, this is manifested by reduced foaming and/or fragrancerelease.

The present inventors have discovered that, by substantially increasingthe viscosity of the liquid composition, these undesirable effects canbe reduced substantially, or even eliminated.

Thus, in accordance with the present invention, there is provided alavatory freshening and/or cleaning system comprising a dispenser fordispensing a liquid composition from under the rim of a lavatory bowl,said liquid composition having a viscosity greater than 2 500 mPa s.

The viscosity is preferably less than 6 000 mPa s and more preferablywithin the range 3 000 to 5 000 mPa s. The most preferred value is about3 500 mPa s.

Typically, such liquid compositions would include surfactants.Surfactants carry out a variety of functions, inter alia, generating offoam during the flush and dissolving or micro-emulsifying any perfumepresent in the liquid composition.

Preferably, the total surfactant concentration is within the range 5 to35 wt. %, the most preferred value being substantially 22.5 wt. %.

Suitable surfactants are anionic and/or non-ionic surfactants, althougha combination of anionic and non-ionic surfactants is particularlydesirable. The preferred anionic surfactant is an alkyl ether sulphate,such at that marketed under the trade name Steol CS 270, containingactive surfactant at a concentration of 70 wt. %, and the preferrednon-ionic surfactant is an ethoxylated synthetic alcohol, such as thatmarketed under the trade name Lutensol AO8.

Optionally, perfume may be present to provide freshening of the lavatorybowl and its vicinity. A suitable perfume for the liquid composition isthat marketed under the trade name Vertana 114.737.

The preferred total concentration of perfume is within the range 4 to 15wt. %, the most preferred value being substantially 6 wt. %.

Although the combination of surfactant and perfume can act as athickening agent, and thus the viscosity of the composition may becontrolled to an extent by the choice of surfactants and/or perfume, thecomposition preferably includes one or more additional thickeningagents, having a preferred total concentration within the range 0.2 to20 wt %. The most preferred concentration of additional thickening agentis substantially 0.40 wt %. A suitable thickening agent is ahydroethylcellulose such as that marketed under the trade name Natrasol250 HHR.

In addition, humectants may be present in the liquid composition.Humectants are desirable when a perfume is present, in order to regulatethe evaporation of the perfume from the composition. Additionally,humectants are useful in preventing phase separation of, andprecipitation from, the composition.

Suitable humectants include glycols, glycoethers, alcohols, sugars andpolyethers.

Optionally, the composition may comprise sequestrants, pH controlagents, dyes and preservatives.

The invention extends to a method of use of such a lavatory fresheningand/or cleaning system in a lavatory bowl.

A preferred embodiment of the present invention incorporates a liquidcomposition having the following components:

Weight Component percent Common name Chemical name type Function WaterWater Solvent 25 Steol CS 270 Sodium Lauryl Anionic Perfume (containingEther Sulphate surfactant solublisation, 70% active form surfactant)generation and viscosity building 5.0 Lutensol AO8 Non-ionic Perfumesurfactant solublisation, form generation and viscosity building 7.00Dipropylene Short-chain Humectant Glycol hydrocarbon 2.00 Dequest 2010Phosphonate Sequestrant 1.60 Sodium Control of pH Hydroxide (32 wt. %aqueous solution) 0.40 Natrasol 250 Cellulosic Thickener HHR 0.005 Dye6.00 Perfume 0.02 Myacide BT Preservative

As can be seen from the above table, the composition comprises Steol CS270. This includes an anionic surfactant at a concentration of 70 wt. %,so that the actual concentration of anionic surfactant in thecomposition is 17.5 wt. %, resulting in a total surfactant concentrationin the composition of 22.5 wt. %.

The resulting viscosity of the above liquid composition is about 3 500mPa s.

1. A lavatory freshening and/or cleaning system comprising a dispenserfor dispensing a liquid composition from under the rim of a lavatorybowl and said liquid composition, said liquid composition having aviscosity greater than 3,000 mPa s at 20° C.
 2. A system as claimed inclaim 1, wherein said liquid composition has a viscosity less than 6,000mPa s at 20° C.
 3. A system as claimed in claim 2, wherein said liquidcomposition has a viscosity within the range 3,000 to 5,000 mPa s at 20°C.
 4. A system as claimed in claim 3, wherein said liquid compositionhas a viscosity of about 3,500 mPa s at 20° C.
 5. A system as claimed inclaim 1, wherein said liquid composition comprises a surfactant.
 6. Asystem as claimed in claim 5, wherein the total surfactant concentrationis within the range 5 to 35 wt. %.
 7. A system as claimed in claim 6,wherein the total surfactant concentration is substantially 22.5 wt. %.8. A system as claimed in claim 5, wherein said surfactant is either ananionic surfactant or a non-ionic surfactant or a combination thereof.9. A system as claimed in claim 8, comprising an alkyl ether sulphateconstituting at least one anionic surfactant.
 10. A system as claimed inclaim 8, comprising an ethoxylated synthetic alcohol constituting atleast one non-ionic surfactant.
 11. A system as claimed in claim 1,wherein said liquid composition further comprises perfume.
 12. A systemas claimed in claim 11, wherein the total perfume concentration iswithin the range 4 to 15 wt. %.
 13. A system as claimed in claim 11,wherein the total perfume concentration is substantially 6 wt. %.
 14. Asystem as claimed in claim 1, wherein said liquid composition comprisesa thickening agent.
 15. A system as claimed in claim 1, wherein saidliquid composition further comprises one or more of sequestrants, pHcontrol agents, dyes and preservatives.
 16. A method of using in alavatory bowl a lavatory freshening and/or cleaning system as claimed inclaim
 1. 17. A lavatory freshening and/or cleaning system comprising adispenser for dispensing a liquid composition from under the rim of alavatory bowl and said liquid composition, said liquid compositioncomprising a thickening agent and having a viscosity greater than 2,500mPa s at 20° C., wherein the concentration of thickening agent, apartfrom any surfactant and perfume which may be present, is within therange 0.2 to 5 wt. %.
 18. A lavatory freshening and/or cleaning systemcomprising a dispenser for dispensing a liquid composition from underthe rim of a lavatory bowl and said liquid composition, said liquidcomposition having a viscosity greater than 3,000 mPa s at 20° C.,wherein said thickening agent is a hydroxyethylcellulose.